Stream water quality is controlled by the interaction of natural and anthropogenic factors over a range of temporal and spatial scales. Among these anthropogenic factors, land cover changes at catchment scale can affect stream water quality. This work aims to evaluate the influence of land use and seasonality on stream water quality in a representative tropical headwater catchment named as Córrego Água Limpa (Sao Paulo, Brasil), which is highly influenced by intensive agricultural activities and urban areas. Two systematic sampling approach campaigns were implemented with six sampling points along the stream of the headwater catchment to evaluate water quality during the rainy and dry seasons. Three replicates were collected at each sampling point in 2011. Electrical conductivity, nitrates, nitrites, sodium superoxide, Chemical Oxygen Demand (DQO), colour, turbidity, suspended solids, soluble solids and total solids were measured. Water quality parameters differed among sampling points, being lower at the headwater sampling point (0m above sea level), and then progressively higher until the last downstream sampling point (2500m above sea level). For the dry season, the mean discharge was 39.5ls⁻¹ (from April to September) whereas 113.0ls⁻¹ were averaged during the rainy season (from October to March). In addition, significant temporal and spatial differences were observed (P<0.05) for the fourteen parameters during the rainy and dry period. The study enhance significant relationships among land use and water quality and its temporal effect, showing seasonal differences between the land use and water quality connection, highlighting the importance of multiple spatial and temporal scales for understanding the impacts of human activities on catchment ecosystem services.

Nitrogen (N) pollution in shallow groundwater within the Jianghan Plain—a depositional basin along the Yangtze River in China—is a serious issue affecting the local water supply. There is little concern regarding temporal variation patterns of groundwater N in regions with intensive groundwater/surface-water interactions thus far. In this study, a 2-year field monitoring program and a set of incubation experiments were jointly applied to characterize the seasonal variation mechanisms of groundwater N. Groundwater monitoring suggested that temporal N variations in monitoring wells of 25 and 10-m depth were correlated with fluctuations in water levels, with lower NH₄-N and higher NO₃⁻-N concentrations corresponding to groundwater discharge during the dry season, and with higher NH₄-N and lower NO₃⁻-N concentrations corresponding to groundwater recharge during the wet season. Batch sediment incubation experiments showed that buried organic carbon in sediments from the field site could not promote NH₄-N release, but exogenous organic carbon and oxidant input could catalyze organic N mineralization, resulting in NH₄-N release. Nevertheless, NO₃⁻-N release was limited in all incubations. Thus, the temporal variation patterns could be divided into (1) groundwater N in type-1 wells (25 and 10 m), controlled by the annual reversal of groundwater flow gradient, which determined whether there was input of exogenous organic carbon or oxidants, ultimately affecting organic N mineralization, denitrification and other transformation processes, and (2) groundwater N in type-2 wells (<4 m depth), which showed no significant seasonal variation, implying the process is mainly controlled by surface inputs in the shallower subsurface.

The objective of this study was to evaluate the inorganic parameters in the water of the Texcoco river. Sampling took place at 10 sites along the watershed (between 2500 and 2240 m above sea level) during the four seasons of the year for three years, with repetitions. The diagnostic parameters and methods used were, for potassium, sodium, magnesium, and calcium, the internal method MI-AM-011 (atomic absorption); phosphates with MI-FQUAR-012, chlorides NMX-AA-073-1981, electrical conductivity and nitrogen of nitrates NOM-AA-93-1984 and NOM-AA-79-1986, pH NMX-AA-08-1980. The three-year average concentrations of calcium, magnesium, potassium, sodium, chlorine, nitrates, and electrical conductivity were low. However, the concentrations of sodium and electrical conductivity were close to medium quality. The concentrations of sodium during Years 2 and 3 were classified as medium. The concentration of phosphates was high. Electrical conductivity during Years 1 and 3 were classified as medium. The concentrations of sodium and electrical conductivity in Seasons 1 and 4 grade a medium quality. The concentration of phosphates during the four seasons and three years were classified as high. Variability of cations and anions at different times of the year was an almost generalized behavior and statistically significant.

En este trabajo se han caracterizado fenotípicamente 83 cepas bacterianas aerobias y 473 bacterias anerobias facultativas gram negativas aisladas de epidermis de rodaballo (Scphthalmus maximus) y del agua de cultivo a lo largo de un año. Se realizó un estudio de taxonomía numérica definiéndose 15 grupos o fenones para cepas no fermentadoras y 66 fenones para cepas fermentadoras. El objetivo del trabajo fue determinar la distribución de los fenones en función de la época de aislamiento y de su origen. Sólo aquellas especies más abundantes (V. fischeri, V. splendidus, V. ordalii) estuvieron presentes a lo largo de todo el año mientras que el resto aparecieron de forma ocasional (V. sophthalmi, V. mediterranei). También se observó que las cepas se distribuyen en función del origen y, por tanto, los aislados de agua de mar son fenotípicamente distintos de los aislados de piel

Most pear (Pyrus communis L.) cultivars are impaired to set fruit under self-pollination, because self-fertilization is prevented by a gametophytic self-incompatibility system. However, accumulated information in this species shows that often for a same cultivar, after self-pollination, a variable response in fruit set can be obtained in different years or growing conditions. In this work, we characterize self-incompatibility and self-fruitfulness in 'Agua de Aranjuez', the main Spanish pear cultivar, which also shows a variable response to self-pollination. Two years with a different fruit setting response after self-pollination, one with no fruit set and the other with a moderate fruit set, were compared for parthenocarpic fruit development and for pollen tube performance. Results show that in both years, this cultivar behaves as self-incompatible with absence of parthenocarpy. In selfed flowers, most pollen tubes are arrested in the upper half of the style, although in a small proportion of the styles, a pollen tube can reach the base of the style and eventually effect fertilization. Self-fertilization, although occurring at a low level, can explain the fruit set levels obtained under self-pollination given that flowers with just one fertilized ovule are able to set fruit. This behavior could explain confusing results about self-fruitfulness in 'Agua de Aranjuez' and other pear cultivars.

Se evaluó el efecto de la época en la calidad de indicadores biofísicos y biológicos del semen. Para ello, se analizó un total de 254 eyaculados recolectados durante un año y procedentes de cuatro sementales bufalinos de 2 a 3 años de edad. La extracción de semen se realizó con vagina artificial, en el horario de 8:00 am a 10:00 am. Se utilizó un régimen de extracción de eyaculados dos veces por semana, los indicadores de calidad seminal evaluados fueron: volumen, motilidad, concentración, porcentaje de espermatozoides vivos, anomalías y el pH. Los datos fueron agrupados por trimestres en correspondencia con las características climáticas y teniendo en cuenta la época de apareamiento espontánea en Cuba (sep-nov, dic-feb, mar-may, jun-ago). Los mayores valores para el índice de temperatura ¡V humedad y la radiación solar fueron observados en el trimestre junio ¡V agosto. Sólo se encontró efecto significativo del trimestre de recolección para el volumen de eyaculados y anomalías espermáticas. El valor más alto de volumen (P0.05), se observó en el trimestre de marzo-mayo y la mayor tasa de anomalías (P 0.001) en el trimestre junio-agosto. Se concluye que las peores condiciones ambientales durante el período junio ¡V agosto incrementa la proporción de anomalías espermáticas. | The effect of the season of the year on the biophysical and biological quality of water buffalo semen was evaluated. For this, a total of 254 ejaculations collected during 1 year from 4 buffalo sires (2 to 3 years old) was analyzed. Semen extraction was carried out using an artificial vagina from 8 to 10 a.m. The ejaculation extraction regime was twice per week, and the seminal quality indicators examined were: volume, motility, concentration, spermatozoa alive, abnormalities and pH. Data were grouped by trimester according to the climatic characteristics and taking into account the spontaneous mating season in Cuba (Sept.-Nov., Dec.-Feb. March-May, June-August). The highest values for temperature-humidity and solar radiation were observed in June-August. There was only found a significant effect of the collection trimester for ejaculation volume and spermatic abnormalities. The highest volume value (P 0.05) was observed in March-May and the highest abnormality rate (P "£ 0.001) in June-August. It is concluded that the worst environmental conditions during June-August increase the proportion of spermatic abnormalities.

In the southwestern United States, precipitation in the high mountains is a primary source of groundwater recharge. Precipitation patterns, soil properties and vegetation largely control the rate and timing of groundwater recharge. The interactions between climate, soil and mountain vegetation thus have important implications for the groundwater supply. This study took place in the Sacramento Mountains, which is the recharge area for multiple regional aquifers in southern New Mexico. The stable isotopes of oxygen and hydrogen were used to determine whether infiltration of precipitation is homogeneously distributed in the soil or whether it is partitioned among soil-water ‘compartments’, from which trees extract water for transpiration as a function of the season. The results indicate that “immobile” or “slow” soil water, which is derived primarily from snowmelt, infiltrates soils in a relatively uniform fashion, filling small pores in the shallow soils. “Mobile” or “fast” soil water, which is mostly associated with summer thunderstorms, infiltrates very quickly through macropores and along preferential flow paths, evading evaporative loss. It was found that throughout the entire year, trees principally use immobile water derived from snowmelt mixed to differing degrees with seasonally available mobile-water sources. The replenishment of these different water pools in soils appears to depend on initial soil-water content, the manner in which the water was introduced to the soil (snowmelt versus intense thunderstorms), and the seasonal variability of the precipitation and evapotranspiration. These results have important implications for the effect of climate change on recharge mechanisms in the Sacramento Mountains.

In the Gran Sasso fissured carbonate aquifer (central Italy), a long-term (2001–2007) spatio-temporal hydrochemical and²²²Rn tracing survey was performed with the goal to investigate groundwater flow and water–rock interaction. Analyses of the physico-chemical parameters, and comparisons of multichemical and characteristic ratios in space and time, and subsequent statistical analyses, permitted a characterisation of the hydrogeology. At the regional scale, groundwater flows from recharge areas to the springs located at the aquifer boundaries, with a gradual increase of mineralisation and temperature along its flowpaths. However, the parameters of each group of springs may significantly deviate from the regional trend owing to fast flows and to the geological setting of the discharge spring areas, as corroborated by statistical data. Along regional flowpaths, the effects of seasonal recharge and lowering of the water table clearly cause changes in ion concentrations over time. This conceptual model was validated by an analysis of the²²²Rn content in groundwater.²²²Rn content, for which temporal variability depends on seasonal fluctuations of the water table, local lithology and the fracture network at the spring discharge areas, was considered as a tracer of the final stages of groundwater flowpaths.

The daily and seasonal variations of water consumption by transpiration and the influence of meteorological parameters on the transpiration intensity were studied in two species of the Fagaceas, Nothofagus obliqua and Notholagus dombeyi.. These species have a wide distribution in Chile and are of- considerable forestry importance. To determine the water consumption of these two species the method proposed by Huber and Ramirez (8) was applied. The experiment was carried out at the meteorological station Isla Tern, of the Austral University of Chile (Valdivia, Chile). The results indicated that increases of solar radiation and air temperature and a decrease of relative humidity lead to an increase in transpiration intensity in both species, which are higher in N. obliqua than in N dombeyi The MatiMUM transpira-don intensities reached were 2 4 1 m 2. in N. obliqua and 1.4 1 in' d" in N dombeyi.. The multiple regression analysis indicated that for both species solar radiation was the most important meteorological factor in regard to transpiration.